1. Field of the Invention
The present invention relates to a powder coating composition curable with actinic radiation which is based on urethane (meth)acrylate and micronized wax and which crosslinks to a light-stable and weather-stable coating film.
2. Description of the Related Art
By actinic radiation is meant electromagnetic radiation such as X-rays, UV radiation, visible light or near IR light (NIR), especially UV radiation, or corpuscular radiation such as electron beams.
Interest is gaining in powder coating materials curable with actinic radiation. The reason lies in the lower thermal load on the substrates, allowing, for example, even wood, wood materials, plastics or certain temperature-sensitive metals or metal alloys to be coated. Moreover, owing to the separation of melting from curing, UV powder coating films display a better surface smoothness than heat-curable powder coating materials. Powder coating materials curable with actinic radiation are described in numerous patents.
Urethane (meth)acrylates represent an important class of binder for radiation-curable powder coating materials. The powder coating compositions produced from them crosslink to light-stable and weather-stable, flexible, and hard films. They are described in, for example, DE 100 58 617, DE 101 63 825, DE 101 63 826 or DE 101 63 827.
The films of these above-described powder coating compositions based on the urethane (meth)acrylates, however, do not possess special surface properties such as, in particular, gloss reduction or texture.